Technical Field
Embodiments of the invention relate generally to visualizing objects within an imaged subject.
Discussion of Art
Coronary artery disease is the narrowing of coronary arteries via the accumulation/buildup of athermanous plaque on the artery wall. An artery that has a significant amount of plaque buildup is commonly known as a “clogged” artery. If left untreated, the flow of blood through a clogged coronary artery may be impaired such that the heart's muscular tissue becomes damaged to the point where it is no longer able to contract. The failure of the heart to contract, commonly known as a heart-attack, is often fatal.
Presently, one method of treating coronary artery disease is an angioplasty procedure which involves inserting an expanding metal mesh, known as a “stent,” within a clogged artery such that the stent expands the circumference of the artery by pressing against the interior wall of the artery. Such stents are typically inserted/deployed within a coronary artery by first placing a collapsed stent over a deflated angioplasty balloon attached to a guide wire. The guide wire, with the attached balloon and collapsed stent, is then inserted into a major artery of a patient's vascular tree that connects to the clogged artery. Next, the guide wire is used to position the stent and balloon at an insertion site within the clogged artery. Once in position, the balloon is inflated, thereby deploying/expanding the stent against the interior wall of the clogged artery. The balloon is then deflated and removed, via the guide wire, from the insertion site.
An angioplasty procedure is typically performed in conjunction with an X-ray fluoroscopy procedure in which a fluoroscopic imaging system provides real time visualizations, hereinafter also referred to as a “live X-ray video feed” or “X-ray video feed,” of the guide wire, balloon, stent, and/or other tools, within an imaged subject (e.g., the patient undergoing the angioplasty procedure). Many fluoroscopic imaging systems provide an X-ray video feed having a resolution at or near fifteen frames per second (“fps”). Stents, however, have a low contrast to noise ratio and are often subject to rapid movements due to a patient's cardiac rhythm. The low contrast to noise ratio and rapid movements typically make it difficult to identify a stent and/or accompanying guide wire within any single frame of an X-ray video feed.
Thus, some current fluoroscopic imaging systems use various image processing technologies to improve visualization of a stent and/or guide wire within a patient's vascular tree. For example, some image processing technologies typically include attaching two objects with a high contrast to noise ratio, known as a “markers,” to the guide wire in relation to the stent. By identifying the position of the markers, some fluoroscopic imaging systems can identify and/or estimate the position of the stent. Currently, such fluoroscopic imaging systems are only able to accurately improve the visualization of a single stent having two markers. Some types of angioplasty procedures, however, such as those for treating a lesion at a bifurcation, involve the placement of two stents which are typically positioned at an insertion site located at the junction of two coronary arteries.
Accordingly, in such angioplasty procedures, it is often the case that the stents must be deployed so that only two markers are visible within any single frame of the live X-ray feed. For example, the stents may be deployed one at a time with each stent being marked by two markers. However, deploying two stents in such a manner increases the duration of the angioplasty procedures and the risk to the patient. Alternatively, the stents may be simultaneously deployed with only one stent being marked by markers. However, deploying two stents in such a manner increases the risk that the unmarked stent will be incorrectly deployed.
What is needed, therefore, is a system and method that enhances the visualization of multiple stents, and/or other low contrast objects, simultaneously within an imaged subject.